Elimination Diet: Definition, Benefits, & Examples​

Elimination Diet: Definition, Benefits, & Examples​

When done carefully and methodically, elimination diets can help identify food allergies and sensitivities. Let’s see what this looks like in practice.

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I have never personally undertaken an elimination diet, but I do have experiential evidence that eliminating one food substance from my diet makes a big difference. In the last year, recognizing that sugary foods seemed (a) very difficult for me to eat in moderation and (b) to be related to mood swings in my daily life, I resolved to stop eating them. I cut out every food with added sugar I could think of. I scrutinized all the processed foods I considered eating, from pasta sauces to crackers to protein bars.

For a few days I craved sugar and felt not-so-great, but after that it seemed like a cloud had lifted from my brain. Suddenly, I could focus on work! I remembered things I needed to do, and then I did them. I found myself more interested in my friends and hobbies, more patient with unexpected challenges. Pretty soon, I was sold on the power of not eating sugar.

My elimination diet was the simplest experimental design you can think of: Make one change and see if other things change afterward. A true elimination diet is a more involved process, starting with the removal of many foods, but the general idea is the same. Let’s look at the science behind elimination diets.​

What Is an Elimination Diet? (A Definition)​

An elimination diet involves changing the foods that a person eats to see if certain undesired symptoms are related to the consumption of those foods (Ly et al., 2017). Typically, every effort is made to remove all potentially harmful foods from one’s diet for a period of time. Then foods are reintroduced into the diet one at a time, with a period of time to observe whether the original physical or mental symptoms return. If those symptoms return in the wake of adding a food, it can be reasonably assumed that the food is partially or fully responsible for the symptoms one is experiencing. With this new knowledge, the person doing the elimination diet is able to decide whether they want to continue avoiding that food or try to eat it in amounts that will not have adverse effects on their health.

Benefits of an Elimination Diet​

Examples of an Elimination Diet

Elimination Diet Meal Plan

Video: How to Do an Elimination Diet

Elimination Diet for IBS​

Many, though not all, people with irritable bowel syndrome (IBS) have sensitivities to food that may cause or worsen their symptoms. For people with IBS who believe they have food sensitivities—which may not reliably show up on food allergy tests—following a specific elimination diet, the FODMAP diet, may be helpful (Smith et al., 2020).
 
The FODMAP diet, which stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols, removes from the diet a variety of carbohydrates that the body finds difficult to digest, thereby reducing the stress and effort placed on one’s digestive system. To achieve a diet that does not include any of these kinds of carbohydrates entails ceasing to eat wheat, onions and garlic, dairy, artificial sweeteners, and some fruits. Although many people find this kind of diet challenging to maintain, they also find it helps with many of their digestive problems (Bellini et al., 2020).

Elimination Diet for Eczema

As we noted above, following an elimination diet may reduce the severity of eczema in our skin. While it can be tricky to determine which foods—and it is usually multiple foods—need to be removed from one’s diet, and nutritional deficiencies may result from removing key foods, permanently removing certain foods from one’s diet does seem to be among the best solutions for treating eczema (Kim et al., 2013).

Elimination Diet for Inflammation

Several elimination diets have been studied for their potential to reduce inflammation in our bodies (Starz et al., 2021), and inflammation is related to several of the chronic medical issues, such as irritable bowel syndrome and eczema, that we have discussed so far. While diets such as the FODMAP diet can reduce inflammation by reducing the amount of contact our digestive systems have with difficult-to-digest foods or foods we are sensitive to, they also run the risk of weakening our immune systems by decreasing the diversity of foods and nutrients we ingest. Again, an effective elimination diet should take into account that key nutrients may need to be acquired elsewhere in one’s diet after the elimination of certain foods.

Elimination Diet for Migraine

Elimination diets also seem to protect some people against migraine (Kelman, 2007). Studies have found that elimination diets protect against the intensity, frequency, and number of migraine symptoms. This is something that many people with migraine have noticed for themselves—they may already know before seeing a doctor that consuming certain foods seems to increase the likelihood they will have a migraine or make the migraine worse than it would otherwise be (Bergh et al., 1987).

Elimination Diet for Gut Health

It is clear that elimination diets alter the composition of our gut microbiota (Díaz et al., 2018). As you might have noticed by now, this is a double-edged sword: While elimination diets can be very helpful for reducing allergic and inflammatory markers in our guts, they can also put us at risk of having too little diversity in our gut microbiota.

Elimination Diet for Depression

As we noted above, an elimination diet may even help people with symptoms of depression  (Karakula-Juchnowicz et al., 2017). Eating high-fat and high-sugar foods while also eating little dietary fiber seems to be associated with depression, perhaps because if we eat lots of inflammatory foods and few anti-inflammatory ones, we put our brains at risk of greater oxidative stress and inflammation (Jones et al., 2017).
 
Researchers have also been interested in the potential for elimination diets to improve symptoms in people with autism spectrum disorder (ASD) and people with ADHD (Ly et al., 2017). At this point in time, there is little research to conclusively suggest that an elimination diet will benefit children or adults with ASD. Meanwhile, the research regarding elimination diets for people with ADHD (which usually involves specifically removing food additives, or the substances added to food to make it stay fresh or look more appealing) suggests that the positive effects are small at best. All that said, these diets may be helpful for people with either diagnosis, so long as adequate nutritional intake is maintained in other ways. 

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References